Citation: Journal of Motor Behavior. :1-17, 2018 Jan 31.Journal: Journal of motor behavior.Published: 2018ISSN: 0022-2895.Full author list: Roh J; Lee SW; Wilger KD.UI/PMID: 29384438.Subject(s): IN PROCESS -- NOT YET INDEXEDInstitution(s): MedStar National Rehabilitation NetworkActivity type: Journal Article.Medline article type(s): Journal ArticleDigital Object Identifier: https://dx.doi.org/10.1080/00222895.2017.1423020 (Click here)Abbreviated citation: J Mot Behav. :1-17, 2018 Jan 31.Abstract: Muscle coordination of isometric force production can be explained by a smaller number of modules. Variability in force output, however, is higher during exploratory/transient force development phases than force maintenance phase, and it is not clear whether the same modular structure underlies both phases. In this study, eight neurologically-intact adults isometrically performed target force matches in 54 directions at hands, and electromyographic (EMG) data from eight muscles were parsed into four sequential phases. Despite the varying degree of motor complexity across phases (significant between-phase differences in EMG-force correlation, angular errors, and between-force correlations), the number/composition of motor modules were found equivalent across phases, suggesting that the CNS systematically modulated activation of the same set of motor modules throughout sequential force development.